Electronic smoking devices, e.g. electronic cigarettes, are intended to allow smokers to inhale nicotine or other aerosols of an aromatic liquid without disturbing other persons. An electronic smoking device typically includes an elongated housing which accommodates a reservoir for a liquid and a device for converting the liquid into an aerosol upon activation of the user. The device for converting the liquid into an aerosol is often referred to as atomizer as it atomizes the liquid, i.e. converts the liquid into an aerosol or vapour.
Several approaches have been suggested for electronic smoking devices. One common approach uses a replaceable capsule which includes an elongated shell having an open end and a closed end. The open end of the capsule is sealed with a puncturable membrane to enclose a liquid which contains the compound or compounds to be vaporized. When the capsule is inserted into the smoking device, a puncture element of an atomizer ruptures the membrane and penetrates into the capsule to come into contact with the liquid contained therein. The puncture element is either formed by, or supports, a metal mesh which transports the liquid by capillary action to a heating section of the atomizer. Upon activation of the atomizer, typically by a user's puff, electrical energy powered by a battery is provided to the heating section to vaporize the liquid. The vaporized liquid is transported by the fluid stream caused by the user's puff to a mouth piece at which the user inhales the vaporized liquid. As the vaporized liquid partially condensates into fine droplets at the transport by the fluid stream to form an aerosol, the action of the atomizer is referred to as “atomizing” the liquid into an “aerosol” which is the product of the atomizer.
Electronic smoking devices of this type are often referred to as three-part electronic cigarettes as they include three main parts—the liquid storage tank or capsule, the atomizer, and the control electronics with the battery. An example of such an electronic smoking device is disclosed in EP 2 443 946 A1 which uses an atomizer having a column shaped alloy sponge that pierces a membrane of a liquid storage tank when the liquid storage tank is inserted into the electronic smoking device. The liquid in the liquid storage tank seeps into the sponge of the atomizer, is transported to a heating coil and is vaporized by the heating element.
While the above approach uses a disposable capsule, other approaches combine a liquid storage container and an atomizer into a single unit which is often referred to as “cartomizer”. As the liquid storage container is not designed to be disposable, the consumed liquid must be replenished by the user. This type of electronic smoking device is also referred to as two-part cigarette as it includes, as main parts, the cartomizer and the control electronics.
Both approaches provide different benefits and drawbacks for the user. For example, replenishing the cartomizer with a liquid may be difficult and inconvenient for the user as the user needs a syringe or pipette to refill the liquid storage container of the cartomizer.
Using disposable small capsules avoids the need for the user to refill the cartomizer as he can simply replace the empty capsule. However, it has been observed that the liquid is not completely drawn into the atomizer so that a portion of the liquid remains in the capsule. The remaining rest of the liquid is disposed together with the capsule which is disadvantageous from both a commercial and environmental perspective.
In view of the above, it is desired to provide a capsule for use with an electronic smoking device with improved depletion of the liquid.